Nitro-paraphenylenediamine derivative and dyeing keratinic fibers therewith



United States Patent 48,4 8 Int. (:1. A61k 7/12 US. Cl. 8-101 ClaimsABSTRACT OF THE DISCLOSURE l-ainino 2nitro-4-(2'-hydroxyethyl)-methylaminobenzene, a new compound, is used todye keratinic fibers, especially living human hair.

Substituted nitro-paraphenylenediamine products are well known as activeingredients in solutions for dyeing keratinic fibers and in particularfor dyeing living hair. The alkyl and hydroxyalkyl groups are especiallywell known as substituents for modifying the shades which may beobtained with nitro-paraphenylenediamine itself.

The object of the present invention is to provide a new dye which is adi-substituted derivative of nitro-paraphenylenediamine. This new dye is1-amino-2-nitro-4-(2- hydroxyethyl)-methylaminobenzene, which has theformula:

CH; 7K /\CH2OH2OH The invention also comprises two new methods ofpreparing the compound according to the above formula.

The first of these methods of preparation is essentially characterizedby the fact that 1-amino-2-nitro-4-methylaminobenzene ishydroxyalkylated by means of a halohydrin, for example.Hydroxyalkylation in the meta position of the nitro group can beeffectuated in commercial quantities, without impurities, especiallywhen using a bromohydrin.

The second method of preparation according to the invention which makesit possible to obtain the compound according to Formula I is essentiallycharacterized by the fact that1-acetamino-4-(2-hydroXyethyl)-methylaminobenzene is nitrated with asulfonitric mixture and that the resulting product is deacetylated bymeans of "ice broad limits, but falls preferably between 10 and 30minutes. The temperature at which these dyes are applied may also bevaried, but in most cases they are preferably applied at roomtemperature. The pH of these solutions is in general between 7 and 10and preferably between 8 and 9.5. An alkali such as plain ammonia, or anorganic base such as an alkylamine, an alkanolamine, or a heterocyclicamine may be used to adjust this pH. The concentration of the dyesaccording to the invention may be varied, but this concentration ispreferably between 0.1% and 3%. It should be noted that the new dye maybe mixed with other nitro, azo or anthraquinone dyes, or any other dyesconventionally used for dyeing hair. A further object of the presentinvention is to provide a new method of dyeing keratinic fibers andespecially human hair, which method is essentially characterized by thesteps of applying to the hair a dyeing composition comprising insolution at least one compound according to Formula I and leaving thiscomposition in contact with the hair for from 10 to 30 minutes. Itshould be emphasized that the compound according to Formula I may alsobe used as a base product in the organic synthesis of tri-substitutedderivatives of nitroparaphenylenediamine. The present inventiontherefore envisages as a particular method of using the compoundsaccording to the invention, a process of synthesizing 1-methylamino-2-nitro-4-(2' hydroxyethyl)-methylamino benzene by using thecompound of Formula I. This process is essentially characterized by thefact that benzenesulfochloride is reacted with the compound of Formula Iso that the former becomes attached to the unsubstituted nitrogen atom.The resulting product is treated with methyl sulfate in an alkalinemedium, and the sulfonylbenzene radical fixed in the first step of theprocess is removed by hydrolysis in a hydrochloric acid medium.

The present invention also envisages, as a particular use for thecompound according to the invention, a process of preparation whichmakes it possible to synthesize 1-(2- hydroxyethyl)-amino 2 nitro-4-(2'hydroxyethyl)- methylaminobenzene. This process is essentiallycharacterized by the fact that chloroethyl-chloroformate is reacted withthe compound according to Formula I to yield the fi-chloroethylic esterof [2-nitro-4-(2'-hydroxyethyl)- methylamino]-phenylcarbamic acid andthis ester is then hydrolyzed with caustic potash purified by solutionin alcohol.

Two methods of preparing the compound according to the invention, andits method of use in hair dyes and as a starting material for thesynthesis of 1-methylamno-2-nitro-4-(2'-hydroxyethyl)-methylaminobenzene and 1-(2'-hydroxyethyl)-amino-2-nitro 4 (2 hydroxyethyl)- methylaminobenzene willnow be described, purely by way of example.

EXAMPLE 1 'First method of preparing l-amino-2-nitro-4-(2'-hydroxyethyl) -methylamino'benzene One mol (167 g.) of1-amino-2-nitro-4-methylaminobenzene'is mixed with 1000 cm. of water and60 g. of calcium carbonate. The mixture is boiled under reflux and 1.2mols (150 g.) of glycol bromohydrin is added drop by drop, whilestirring. After boiling under reflux for two hours, 1500 cm. of boilingwater is added, and after having continued the reflux for severalminutes, the mixture is filtered through a funnel for hot filtration.After cooling, the filtrate yields 161 g. of the crude product, which,after two recrystallizations in methylisobutylketone, melts at C.

Analysis of end product: Calculated for C H O N (percent): C, 51.18; H,6.16; N, 19.90. Found (percent): C, 50.8950.98; H, 6.l66.43; N,20.21-20.23.

3 EXAMPLE 2 (a) First step: nitratin.-0.1 mol (21 g.) ofl-acetamino-4-(2-hydroxyethyl)-methylarninobenzene is dissolved in 75cm. of concentrated sulfuric acid, while keeping the temperature between0 and 2 C. A sulfonitric mixture formed by adding 6.6 g. of concentratedsulfuric acid to 6.6 g. of nitric acid having a density of 1.52 is thenadded immediately, little by little, while stirring and keeping thetemperature between 0 and 2 C. The reaction mixture is then poured overice, and neutralized with ammonia to extract the isopropyl alcohol.After having eliminated this alcohol under vacuum 23.5 g. of crude1-acetamino-2-nitro-4-(2'-hydroxyethyl) aminobenzene is obtained. (b)Second step: deacetylation and purificati0n.The acetylated derivativeobtained in the first step is introduced into a mixture of 30 cm. ofconcentrated hydrochloric acid and 60 cm. of water. This is kept for /2hour in a boiling water bath. A little animal black is added, theproduct is filtered, and after drying and cooling yields 16 g. ofcrystallized hydrochloride. This is dissolved in boiling water, which isrendered alkaline by adding ammonia, cooled, and on drying yields 13 g.of 1-amino-2-nitro-4-(2 hydroxyethyl) methylaminobenzene, whichafterrecrystallization in chloroform, melts at 115 C.

Analysis of end product: Calculated for C H O N (percent): C, 51.18; H,6.16; N, 19.90. Found (percent): C, 51.16-51.22; H, 6.12-6.42; N,20.03-20.03.

EXAMPLE 3 The following composition is prepared:

1-amino-2-nitro-4-(2 hydroxyethyl) methylaminobenzene-0.75 g.

Polyoxyether of fatty alcohol (Remcopal 21.411 sold by Paix) g.

20% ammonia q.s.p.pH=8

Water, q.s.p.-100 g.

This solution is applied to white hair and left in contact therewith forminutes. The hair is then rinsed, shampooed and dried. The result is avery slightly mauve rose blond shade.

EXAMPLE 4 The following composition is prepared:

1-amino-2-nitro-4-(2 hydroxyethyl) methylaminobenzene0.75 g.

1-methylamino-2-nitro-4-(fl-hydroxyethyl)-methylaminobenzene0.5 g.

Polyoxyether of fatty alcohol (Remc'opal 21.411 sold I by Paix)5 g.

20% ammonia q.s.p.pH=8

Water, q.s.p.lOO g.

This solution is applied to light chestnut hair and left in contacttherewith for 10 minutes. The air is then rinsed, shampooed and dried. Alight chestnut with glints of violine results.

EXAMPLE 5 The following composition is prepared:

1-amino-2-nitro-4-(2 -hydroxyethyl) methylaminobenzene0.75 g.

1-( -diethyl-aminopropyl) -amino-2-zimino-4-nitro benzene-0.01 g.

Polyoxyether of fatty alcohol (Remcopal 21.411 sold by Paix)-5 g.

20% ammonia q.s.p.pH=8

Water, q.s.p.100 g.

This solution is applied to 100% white hair and left in contacttherewith for 20 minutes. The hair is then rinsed, shampooed, and dried.A warm, slightly pearlescent blond shade results.

. EXAMPLE 6 Use of 1-amino-2-nitro-4(2-hydroxyethyl)-methylaminobenzeneto synthesize 1-methylamino-2-nitro-4-(2- hydroxyethyl)-methylaminobenzene (a) First step: tosylatiom-A solution is preparedcomprising 0.15 mol (31.65 g.) of 1-amino-2-nitro-4-(2'-hydroxyethyl)-methylaminobenzene in 110 cm. of pyridine. 0.15 mol (19.2cm. of benzene-sulfochloride is added little by little, while stirring,at between 45 and 50 C. The reaction mixture is kept at 45 C. for 2hours and then poured into a liter of ice water which contains cm. ofconcentrated hydrochloric acid, thus precipitating a brown resinousproduct which is then redissolved in methylisobutyl-ketone. Themethylisobutyl-ketone solution is then extracted, using a normal sodiumhydroxide solution, and the residual solution is neutralized withhydrochloric acid. On drying, this yields 36 g. of l-benzenesulfonylamino-2-nitro-4-(2-hydroxyethyl) methylaminobenzene, which,after recrystallization in alcohol, melts at 112 C.

Analysis of end product.Calculated for C15H17N3O5S (percent): C, 51.28;H, 4.84; N, 11.96. Found (percent): C, 51.56-51.39; H, 4.69-4.94; N,12.05-12.01.

(b) Second step: alkylation.-A solution containing 0.0142 mol (5 g.) ofthe product. obtained in the first step in 65 cm. of 0.5 N sodiumhydroxide is prepared. To this solution, 0.032 mol (3 cm?) of methylsulfate is added, while keeping the temperature between 25 and 30 C. Thereaction mixture is left for two hours at this temperature, and aftercooling and drying, yields 4 g. of 1- (benzene sulfonyl)-methylamino2-nitro-4-(2-hydroxyethyl)-methylaminobenzene. 50 cm. of 0.5 N sodiumhydroxide is added to this product, while stirring, to eliminate any ofthe starting product which has not reacted. The product is then dried,washed with water, and recyrstallized in a mixture of 75% ethyl acetateand 25% petroleum ether, yielding 3.6 g of the pure product, which meltsat 116 C.

Analysis of end product.Calculated for C H N O S (percent): C, 52.60; H,5.20; N, 11.50. Found (percent): C, 52.87-52.70; H, 5.44-5.26; N,11.43-11.63.

(c) Third step: hydrolysis.A solution of 0.028 mol (10.22 g.) of theproduct obtained in the first step in 25 cm. of concentratedhydrochloricacid mixed with 5 cm. of water is heated for an hour in a boiling waterbath. After cooling and dilution, the solution is neutralized withsodium hydroxide and on drying yields 5.1 g. ofl-methylamino-2-nitro-4-(2'-hydroxyethyl) methylaminobenzene,

which is practically pure, and melts at 94 C.

Analysis of end product-Calculated for C H O N (percent): C, 53.33;H,6.67; N. Found (percent): C, 53.71-53.74; H, 6.46-6.93.

EXAMPLE 7 Use of 1-amino-2-nitro-4-(2-hydroxyethyl) -methylamino benzeneto synthesize l-(2'hydroxyethyl)-amino-2-nitro- 4-(2'-hydroxyethyl)-methylaminobenzene (a) First step: producing anester.0.1 mol 21.1 g.) I

cooled an dried, yielding 12.2 g. of the starting product in the form ofthe hydrochloride. The filtrate is evaporated under vacuum and yields16.5 g. of the chloroethylic ester of [2nitro-4-(2(hydroxyethyl)-methylamino] -phenylcarbamic acid.

(b) Second step: hydrolysis.-The ester obtained in the first step isdissolved in 135 cm. of a solution of caustic potash in alcoholcontaining 110 g. of potash per liter. This solution is heated to refluxfor two hours, and then cooled and poured into 600 cm. of ice water.This is then extracted with methyl-isobutyl-ketone and the solventevaporated under vacuum. The yield is 11 g. of 1-(2-hydroxyethyD-amino-Z nitro-4-(2'-hydroxyethyl)-methylaminobenzene,which, after recrystallization in benzene, melts at 99 C.

Analysis of end product.Calculated for C H N O (percent): C, 51.76; H,6.66; N, 16.47. Found (percent): C, 51.26-51.61; H, 6.66-6.68; N,16.27-16.53.

It will of course be appreciated that the methods of producing and usingthe products which have just been described have been given purely byway of example, and may be modified as to detail without therebydeparting from the basic principles of the invention.

What is claimed is:

1. 1 amino-2-nitro-4-(2'-hydroxyethyl)-methylaminobenzene.

2. A composition for dyeing keratinic fibers comprising dyeing amountsof the compound of claim 1 in an aqueous solution having a pH between 7to 10.

3. A composition as claimed in claim 2 in which the concentration ofsaid compound lies between 0.1% and 3% inclusive.

4. The method of dyeing keratinic fibers which comprises the steps ofapplying the composition claimed in claim 2 thereto, and leaving saidcomposition in contact with said fibers for between 10 and minutes,inclusive.

5. The method of claim 4, wherein said keratinic fibers are live humanhair.

References Cited UNITED STATES PATENTS 2,687,431 8/1954 Marschall260573X 2,750,326 6/ 1956 Eckardt I 167-88 2,750,327 6/ 1956 Eckardt II16788 3,088,878 5/1963 Brunner et al. I l6788 3,168,442 2/1965 Brunneret al. II 167-88 3,194,838 7/1965 Ross 260-573 OTHER REFERENCES ALBERTT. MEYERS, Primary Examiner V. C. CLARKE, Assistant Examiner U.S. Cl.X.R.

